Power drive for tools



July 29,1941. R. F; KRQEG'ER Em 2 250 4 POWER DR-IVE FOR TOOLS 2 Sheets-Sheet 1 Filed April 26, 1940 ATTORN Y.

y 1941- R. F. KRUEGER ETAL 2,250,534

POWER DRIVE FOR TOOLS 1 Filed April 26, 1940 2 Sheets-Sheet 2 Patented July 29, 1941 PO'VVER DRIVE FOR TOOLS a V obert F. Krueger and John L, Detroit, Mich. 1

Application April 26, mo sten No. 331,742 J i 4 Glaims (0114- 52) Our present invention relates in general to improved means for converting motion from one form into another, and relates more specifically to' improvements in the construction and operation of mechanism for transforming continuous rotary motion into uniform reciprocating movement especially adapted for the propulsion of tools such as files.

"Generally defined, an object of our present invention is toprovide a new and useful motion transforming mechanism especially adapted to convert continuous rotary motion into uniform reciprocating. movement.

';Some of the more specific objects of our in vention are as follows:

j To provide an improved power drive for reciprocabletools such asfils. which is simple and compact in construction, and highly efiicient in use.

. To provide an improved motion converting assemblage which is capable of effectively transforming relatively high speed rotary motion into relatively slow I and long stroke reciprocating movement or motion of translation.

To provide an extremely durable and compact driving assembly for portable tools, which can be conveniently manipulated without danger to the operator.

To'providean improved fluid pressure operated driving rig for reciprocable tools which require relatively smooth and uniform motion of translation during normal operation.

"To provide a portable tool drive which may be confined within the manipulating handle,

which requires minimum attention, and which maybe manufactured and operated at moderate cost.

To provide a relatively'simple'and exceedingly compact motion transferring and converting mechanism which is susceptible of diverse applications.

- These and other specific objects and advanfages of the-invention will be apparent from the following detailed description.

' A clear conception of an embodiment of the features constituting our present improvement, and of the mode of construction and of manipulating a power drive for reciprocable tools built in accordance with the invention, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a part sectional side view of an air motor driven portable file, with the guide plate removed; q I a p Fig. 2 is a central vertical section through the assemblage of Fig. 1, takenalong the line 2-4; Fig. 3 is a transversevertical section through the driving'and' motion converting as'semblyof Fig. 2, taken along the irregular 1ine.3.-'-.3;;j .2; Fig. 4 is a.horizontalsection through'thelassemblagejof Fig. 2, taken along: the line-4+4;

Fig. 5 is another "horizontal secti'on'through' the assemblage. of Fig.2, alongtheline Fig; 6. is a fragment connected by" a jaw chucky l' Fig..'7 is 'a' side viewsiinilarto-that: of.Fig:x1, and showing the file carrier in extreme forward" position; v i

Fig.8 is another similar viewgshovs ringthe file carrier moved back to mid-position;

Fig. 9 is still another similar view showing the file carrying slide moved rearwardly to its ex-' treme'positiomand Fig. 10 is an additional scribed herein as being embodied ma rotary air motor driven assemblage-especially adapted to reciprocate a filev or the like, it is not our-dc sire or' intentto-thereby unnecessarily restrict' the scope or; utilitymf' the motion converting V mechanism. I Y

Referring to the comprises in generalarotary air-operated propelling motor having -a rotor l4 mounted on a drive shaft l5 and provided with blades l5"co+, operating with an enclosing casing or housing i'i;'apinion it carried by an end of the rotary shaft-i5 and coacting with a rotary internal gear is secured to one end'of a driven shaft 20 jour'- nalled in a bearing 2| 'carried'by-another cas ing 22-; a crank '23 formed integraliwith the op-- posite endof the driven shaft 20 and having a crank pin 24 upon which a gear 25 is 'rotatably supported; a fixedv annular toothed element or rack 25 secured to the casing 22 and having-.in-.-

ternal teeth 21 with'which the teeth of the gear- 25 have rolling coaction; a second crank-28 rigrocable; and a chuck 35 carried by an end of the .of the 'iile: carrying slide and of a' filefthese elements being detachablyi similar view, 1 showing i the file'carrier moved forwardly tomid-positiom' While our invention-has been shown and 'dedrawings, the improved port able tool driving assemblage illustrated therein,"

slide 32 and adapted to firmly but detachably secure a tool such as a file 36, to the slide bar 32.

The air-operated propelling motor has a circular displacement chamber 31 disposed eccentrically of the rotor shaft l and within the housing l1, and the rotor blades |6 are slidable in radial slots 38 in the rotor I4 and are constantly urged toward and into contact with the annular wall of the chamber 31 by means of helical compression springs 39. The rotor confining chamber 3|is enclosed by'a removable closure plate or cover 40 and has a tangential air inlet opening 4| andv an air exhaust opening 42, as shown in Fig. 5. The inlet opening 4| communicates with ,asupply pipe 43 having a control valve 44 therein, and adapted for attachment to a flexible air supply hose not shown; and the drive shaft l5 may be journalled in self-lubricated bearings 45,..45 carried by the housing l1 and cover Ill]v respectively, and may be secure-d to the rotor M 'by meansgof a key 41. The cover 4-!) and housing |'I may be detachably secured to each other-and to the casing 22 by means of screws 48; and the pinion l8 whichisqcarried by the drive shaft [5, is located within.achamberH-iormed within the casing-.22 and in which the internal gear 19 is located.

.The internal gear Ill-with which the; pinion l8 coacts, may be formed sufiici'ently heavy to provide' desirable flywheel-effect, and since the pinion l8 has relatively small? diameter as compared to the pitch diameter of the gear IS, the latter will naturally rotate at considerably slower speed. The gear |9' maybe firmly attached to the driven shaft 20 by'anut 50, and the bearing 2i may also be. 015a self-lubricating type although lubrioantmay be confined within the chamber 49. As previously indicated, the crank 23 is formed integral with the shaft 20; and the gear 25 which is rotatably supported by the crank pin2 4, has a pitch diameter approximately onehalf as great as the pitch diameter of the annular stationary rack 26, so that the rack has twice the number of teeth 21-! as has the gear 25; The crank :28 is firmly attached to the revolving gear '25, and by Virtue of the fact that this gear-25 coaots with the teeth 21' of the fixed annular rack 26, the crank pin 29 will revolve about theaxi's of the crank pin 24 but in a direction oppositeto the direction of revolution of the crank '23, during rotation of the shaft 29. The ratio of the gear teeth to the rack teeth 21 is-however such, that the rotation of the gear 25 caused by the rack teeth 21, will cause the axis orthe crank pin '29 to traverse a rectilinear path-in the central plane of the guideway 34, at alI times.

The gear 25 is revolv-able within a chamber 5| in which the rack 2-6 is also confined, and the crank pin 29 has a snug fit in the opening 30 of the slide 32. The-slide-32 is freely reciprocable'in the guide-way 34 of the guide member 33, and this member may be detachably secured to the casing 22 by-means of screws 52. The chuck 35 -which is carried by-the end of the reciprocable slide 32, comprises tapered jaws 53 and a clamping collar 54 coa-cting with the jaws 53 and with screw threads 55 formed on the slide 32. The jaws -53 areadapted to firmly engage the shank 56 of a file 36 or other tool which is to be reciprocated', and the housing l1 and casing 2-2 serve as a handle for efiecting manipulation and transportation of the portable tool assemblage.

Duringnorm-al operation of' the improved portable tool the control valve 44 may be set to admit more or less air under pressure to the chamber 31 through the tangential inlet 4|, thereby causing the rotor l4 to revolve at relatively high speed and to rotate the shaft l5 and pinion l8 at corresponding speed. The rotation of the pinion 8 is imparted to the shaft 20 through the internal gear l9, but at considerably reduced speed; and as the shaft 20 revolvesthe crank 23, the crank pin 24 and'gear 25 are caused to traverse an orbital path with the teeth of the gear rolling along the internal teeth 21 of the fixed rack 25. While the gear 25 is being carried about the axis of the shaft 20 in a clockwise direction asviewed in Figs. 1 and 7 to 10 inclusive; due to its coaction with the rack teeth 21, this gear 25 will simultaneously rotate about the axis of the crank pin 24 in a counter-clock- Wise direction, thereby causing the slide driving crank pin 29 to traverse a rectilinear path and to reciprocate the slide 32. The total travel of the pin .29 approximately equal to the pitch diameter of the fixed rack 26, and when the gear 25 isipositioned as in Fig. 7 the pin 29 will be to the extreme left, whereas shifting of this gear t-othe position shown in Fig. 9' will position the pin 29 to the extreme right. When the gear 25 is in either of the intermediate positions shown in Figs. 8 and 10, the crank pin 29 Will be in mid-position with its axis disposed in the central plane of the slide 32. In this manner, the slide 32 will be reciprocated through a relatively long stroke and with uniform speed, with the aid of a crank 23 having relatively short radius of swing. 1 7

From the foregoing detailed description, it will be apparent that our invention provides a mo-' tion transforming mechanism adapted to convert relatively high speed continuous rotary mo- 7 tion into uniform reciprocating movement having a. relatively long stroke, and that the improvement is especially useful for the purpose ofdriving tools such as files or the like. The assemblage is obviously extremely simple, compact and highly efiicient, since no slippage can occur between the driving 'motor and the reciprocating slide 32. The entire assemblage can be conveniently housed within a relatively compact casing which can'be utilized as a manipulating handle forthe tool, and all part-sci the assemblage are effectively protected. against possible damagewhile still being readily accessible for inspection. Although the improved mechanical movement 'is especially useful for the purpose of driving tools r such as files, it can also be utilized for any other purpose where it is desired to secure relatively long stroke reciprocation at uniform speed and where the driving power is derived from a rotary source. The assemblage canalso be manufactured and operated at moderate cost and requires.

little attention after proper construction and assembly thereof. The invention has proven highly successful and satisfactory for the purpose of driving tools such as files, and because of the compactness of the driving mechanism, tools of this type can be operated in any desired position.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of use, herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

We claim:

1. In combination, a casing having a fixed central bearing and a fixed rectilinear guide extending approximately equidistant across the axis of said bearing, a rotary shaft journalled in said bearing and having thereon a crank pin which is revolvable about said axis, a gear journalled on said pin and having thereon another crank pin revolvable about the axis of rotation of the gear and movable along said fixed guide, a fixed rack for rotating said gear about its own axis, and a slide reciprocable along said guide by said other crank pin.

2. In combination, an approximately cylindrical casing having a fixed central bearing and a fixed rectilinear guide at one end of the casing and extending across and approximately equidistant on opposite sides of said bearing, a rotary shaft journalled in said bearing and having at one end thereof a crank pin revolvable about the axis of rotation of the shaft, a rotary motor coacting with the opposite end of said shaft to rotate the latter, a gear journalled on said pin and having an eccentric bearing portion movable along said fixed guide, an annular toothed element secured within said casing coacting with said gear to rotate the same about its own axis, and a member reciprocable along said guide by said bearing portion.

3. In combination, an approximately cylindrical casing forming a handle and having therein a central bearing and a fixed transverse guide at one end of said bearing and projecting approximately equidistant on opposite sides thereof, a rotary shaft journalled in said bearing and having one end provided with an eccentric crank pin, a rotary motor housed within and near the central axis of said casing and cooperating with the opposite end of said shaft to rotate the same Within said bearing, a gear journalled on said crank pin and having an eccentric projection extending into said fixed guide, an annular rack fixed within said casing and coacting with said gear to rotate the latter, and a reciprocable slide coacting with said fixed guide and with said gear projection.

4. In combination, an approximately cylindrical casing forming a handle and having therein a central bearing, a fixed transverse rectilinear guide spanning said bearing at one end of the casing and extending approximately equidistant on opposite sides of the bearing, a rotary shaft journalled in said bearing and having one end provided with an eccentric crank pin and its opposite end provided with an internal gear, a rotary propelling motor housed within said casing near the central axis of said bearing and having a pinion drivingly engaging said internal gear, a spur gear journalled on said crank pin and having an eccentric pin projecting therefrom into said fixed guide, an annular rack fixed Within said casing and coacting with said spur gear to rotate the latter, and a reciprocable slide coacting with said fixed guide and with said eccentric gear pin.

ROBERT F. KRUEGER. JOHN L. KRUE'GER. 

